Why does pituitary disease affect fertility?

Both the ovaries and testes need pituitary function to perform their actions. As well as being the glands responsible for production of oestrogen and testosterone respectively, these glands are vital for successful conception. If neither of these glands receive the LH and FSH from the pituitary gland then they are unable to mature and release oocyte (egg) in the case of the ovary, or to produce and hold sperm in the testes.

The most common pituitary condition resulting in fertility issues is a prolactinoma. This can result in loss of menstrual periods or loss of ability to make sperm, thereby reducing or stopping the ability to conceive.

Loss of gonadotroph function (LH/FSH) results in the loss of menstrual cycles due to loss of ovarian function. This results in failure to maturation and release oocyte (egg), or results in the loss of stimulus to the testes to induce sperm production, resulting in low or nil sperm count.

Can conception still happen with pituitary disease?

Prolactinoma: this is often achieved by controlling the excess prolactin with a dopamine agonist, most often Cabergoline. The effect of this class of drug is to 1) lower the prolactin with the aim being of a return to within normal limits and 2) over a period of three to five years of shrinking the adenoma. Smaller adenomas can be more successfully reduced in the shorter time frame, whilst larger adenomas may take an extended period of treatment to shrink.

Conception through natural methods is often possible once prolactin levels have returned to within normal limits.

Care should be taken with regards to continued use of the dopamine agonist during a pregnancy. Monitoring of prolactin serves little purpose as this hormone would naturally increase during pregnancy. MRI scanning is generally not pursued during pregnancy unless significant or life-threatening illness were to present.

Loss of gonadotroph function: this can present a more complex problem. To achieve conception, either ovary or testes will need to be stimulated to produce egg/sperm respectively. This is generally managed by a specialised fertility team –often through gynaecology services.

Injection of stimulating hormones is the common form of treatment with drugs, such as Follitropin Alfa, Leutropin Alfa and Human Chorionic Gonadotrophin (hCG) being used. It is likely that these injections will be self-administered and so you should expect to be taught how to do this.

The fertility team will alert you to the possible side effects, mainly some pain or irritation at the injection sites and acne can develop. With ovarian stimulation, a rare side effect of ovarian hyperstimulation syndrome can sometimes occur. The fertility team treating you will be sure that you can recognise the signs of this. If this does happen it may lead to a temporary discontinuation of the treatment.

Regular pelvic ultrasound scans and/or monitoring of blood levels of oestrogen can be used to determine the timing of the hCG injection.

Sperm cycles are on average 70 days duration, and treatment with Follitropin alfa and hCG may be needed for six to 12 months before achieving sperm counts adequate for conception.

What should I do if I want to conceive?

Firstly, contact should be with your endocrine team to discuss this. Let your consultant know that you want to try to conceive. They can then set in place any other specialist referrals that may be needed. They will also most likely be involved in the monitoring of your pituitary disease through any successful pregnancy, although this may be through a specialised combined obstetric and endocrine clinic.

The contact with your endocrine team is also important if you are currently in the diagnosis stage and working towards treatment of, or surgery, for your pituitary disease. It may be possible before treatment is underway to be referred for sperm banking as an example. So, keeping your endocrine consultant aware of your possible future plans can be beneficial when making treatment decisions.